Production of containers

ABSTRACT

A method of producing containers in which one strip element is folded to provide uniform, transverse, channel-shaped portions and a second strip member is placed over the channel-shaped portions, the lateral, longitudinal side edges of the member being folded down against the edges of the channel-shaped portions and sealed thereto to form a container. The side edges of the member being cut to provide transverse slits therein to form flaps of a size to cover the open ends of each channelshaped portion to thus facilitate manufacture of the containers.

United States Patent [1 1- Stark 1 1 Oct. 30, I973 l l PRODUCTION OF CONTAINERS {75] Inventor: Sven 0101' Siiren Stark, Rydsgard,

Sweden [73] Assignee: Tetra Pak Developpement SA,

Lausanne, Switzerland 221 Filed: Aug. 4, 1972 21 Appl. No.: 278,056

[30] Foreign Application Priority Data Aug, 20, 1971 Germany P 21 41 892.8

[52] US. Cl 93/36 R, 93/39 R, 93/45, 93/55, 93/DIG. 1

[51] Int. Cl ..L 8311) 17/26, B31b 17/60 [58] Field of Search 93/36 R, 55, 55.1, 93/1 H, 43,56, 39 R, l R, 45, 46, 47, 48;

[56] References Cited UNITED STATES PATENTS 3,698,624 10/1972 Stark .,22'9/23R 1,997,718 Clalf .L 93/45 X 4/1935 3,315,435 4/1967 Gunyou.... 93/56 R 815,479 3/1906 Sheldon 93/55 X FOREIGN PATENTS OR APPLICATIONS 186,479 11/1963 Sweden ..93/ I H Primary Examiner-Andrew R. J uhasz Assistant Examiner.lames F. Coan Attorney Pierce, Scheffler & Parker [57] ABSTRACT A method of producing containers in which one strip element is folded to provide uniform, transverse, channel-shaped portions and a second strip member is placed over the channel-shaped portions, the lateral, longitudinal side edges of the member being folded down against the edges of the channel-shaped portions and sealed thereto to form a container. The side edges of the member being cut to provide transverse slits therein'to form flaps of a size to cover the open ends of each channel-shaped portion to thus facilitate manufacture of the containers.

8 Claims, 2 Drawing Figures PRODUCTION OF CONTAINERS This invention relates to the production of containers, and more especially containers formed by folding a first strip or web of packaging material transversely at selected points along its length to set up the strip or web into a scalloped, or transversely fluted or -channelled form, and affixing a second strip or web, substantially alignedwith the first strip or web, to the upstanding transverse folds of thefirst strip or web, the edge zones of the second strip or web being folded down to close the ends of the recesses or cavities formed, by the said folding, in the first strip or web.

A method of producing containers in the aforesaid manner is described in the specification of copending patent application No. Ser. 43,119/70 now U.S. Pat. No. 3,698,624, and the present invention may be 'regarded as an improvement in or modification of the previously described method, whereby production is facilitated.

The invention consists in a method of producing containers wherein a first strip or web of packaging material is formed, by upstandingtransverse folds with a series of transverse open-ended channels or recesses, a second strip or web of packaging material is applied to the upper edges of said transverse folds, and the side zonesof said second strip folded. down against the end edges of said channels or recesses to close the open ends thereof, the contacting lines or areas of the two strips or websbeing thereafter sealed together in order to form a closed container, wherein the foldable edge zones of said second strip or web are divided into separated flaps by cuts extending inwards from the edges before being sealed to the first strip or web.

The cuts may extend inwards from the edges of the second strip or web substantially to the fold lines of the edge zones. Each flap is preferably so dimensioned as to close an end of one recess of channel formed in the first stripor web. The cutting of the edge zones to form the flaps is preferably carried out while the second strip or web is in a flat condition. Apart from'the cutting of the edge zone of one web into flaps, as indicated above, the procedure for advancing. the webs, bringing and sealing them together, filling the containers so formed, and sealing and separating'thern, may be substantially in the same manner as described in the abovementioned prior application.

The invention further consists in a container whenever produced by the method as specified in the next preceding paragraph.

The invention will be clearly understood from the following description of one form thereof, and this description will be more readily followed by reference to the accompanying drawings wherein FIG. 1 shows diagrammatically in the course of carrying out the method in accordance with theinvention, a preformed first strip of packaging material, i.e. a strip provided with a row of transverse channel-shaped sections and also a second stripabove the first strip and already providedwith cuts or slots to form flaps, of which the foremost pair is shown as. being bent or folded inwards, and

As shown in FIG. 1 a first strip 13 of relatively stiff packaging material is folded transversely in such a way that channel-shaped sections or recesses 2 are formed. These are situated behind one another, each channelshaped section being provided with walls 14 connected together at the upper folds 16 by means of short connectors l7.

A second strip 3, also of relatively stiff, and preferably the same material, is suitably indented or otherwise provided with a line of weakness to form fold lines 12 parallel to each edge, and'defining edge zones foldable downwards as seen in FIG. 1.

In accordance with the invention the side zones of the web 3 are divided by spaced cuts or slits 23!), extending from the edge of the web on each side to the fold lines 12, into side flaps, 23, 23a etc. Each flap is so dimensioned that when folded down, as illustrated it abuts the edges of a channel recess 2 and closes the end of the recess when bondedto the edges of the web 13 and walls 14, while the central part of the web 3 is bonded to the transverse connectors 17.

The folding-in of the flaps 23' separated by the slits 23b is facilitated as will be seen from an examination of the foremost pair of flaps (FIG. 1), which as illus trated already substantially form the legs or end closures of the channel-shaped recess 1, the legs being connected by the mid-portion 29 of web 3. The transverse width of the mid-portion 29 of the web 3 is approximately the same as the width of the strip 13, and the width of each flap is approximately equal to the distance between adjacent legs 14 of a channel-shaped recess 2, so that when the web 29 is brought into contact with the top folded edges 16 of the walls 14 of the appropriate channel-shaped recess 2, the sides of the flaps 23 with the end edges of the walls 14, and the side edges of the flaps 23 with the outer edges of the walls of the appropriate channel-shaped recess2, all these surfaces can be joined together at these edges to form a liquid-tight joint. As regards the connecting pieces 17 which connect the walls 14 of adjacent channel-shaped recesses 2, it is preferred that the :slots 23b shall be approximately of the same width as, or only slightly narrower than, the connecting pieces 17.

In FIG. 2 it is shown how the first -strip 13 which is folded into channel-shaped sections is located in the forming parts 25 which forming parts are provided with spaced, upright separating walls 26over which the strip 13 is formed. In order to make it possible to seal the inside surface of the flaps 23 of the second strip 3 against the side edges of the channel-shaped strip 13 it is necessary to dimension the width of the first strip 13 in such a way, that it is somewhat wider than the forming parts 25, in order the ensure that the side edges of the channel-shaped recesses 2 orsections 2 project somewhat from the side edges of the forming parts 25.

When the flaps 23 have'been folded down and sealed against the folded strip 13 along the sealing zones 10,

the formed hollow spaces are filled with the help of afilling tube (not shown), which is located underneath the strip 3, whereafter the parts 17 of the folded strip 13 which are located against the upper end surface of the upright separating walls 26 of the forming parts 25, are sealed against the inside surface of the strip 3 along the sealing area 16 by means of the sealing device 27, which can be an ultrasonic sealing device or a heat sealing device.

The sealing of the flaps-23 against the side edges of the folded strip 13 can preferably be performed by means of heat and the sealing operation can be done in such a way, that the inside of the flaps 23 and perhaps even the side edges of the folded strip 13 are heated by means of hot air or heat radiation, whereafter pressure devices (not shown) fold and press the flaps 23 against the side edges of the folded strip 13 in such a way, that a tight and mechanically strong seal is obtained. Of course the slits 23b in the second strip 3 must be located in such a way, that the slits when the flaps are folded down will be located just over one of the upright folds in the first strip 13. The filled and sealed packaging containers 30 are separated from each other by means of a cutting device 100 which is arranged to cut through the joined strips 3 and 13 in the area 17.

in order to facilitate the joining operation, it is preferred to make both strips from a thermoplastic material e.g., foamed sheet of polystyrene or other plastics material, or at least from a material provided with a thermoplastic layer along the contact lines or surfaces.

1 claim:

1. A method of producing containers comprising folding a first strip element of foldable packaging material transversely of its length to form a plurality of uniform, transverse, channel-shaped portions in a continuous series in the element, applying a second strip member of foldable packaging material to the upper edges of the the transverse channel-shaped portions, forming spaced, transverse cuts along the edges of the second strip member to form flaps, said cuts extending inwardly from the outer edges of the second strip member, folding the lateral longitudinal side edges of the second strip member down against the end edges of the transverse, channel-shaped portions to close the open ends thereof, portions of the inner surface of the second strip member contacting the edges of the first strip element and sealing the contacting inner surface portions to the edges, the step of forming the cuts preceeding the step of sealing the contacting inner surface portions to the edges.

2. A method as claimed in claim 1 and further comprising forming in the second strip member two spaced, parallel, longitudinal fold lines inwardly of the edges thereof, the cuts extending from the edges of the second strip member inwardly to the adjacent fold lines.

3. A method as claimed in claim 1 wherein each flap formed by the spaced, transverse cuts has a width and a length at least equal to the width and the length, respectively of the transverse channel-shaped portions of the first strip element.

4. A method as claimed in claim 1 wherein the cuts are formed along the edges of the second strip member before the longitudinal side edges of the second strip member are folded down against the end edges of the transverse, channel-shaped portions of the first strip element.

5. A method as claimed in claim 2 wherein the central longitudinal portion of the second strip member between the fold lines is sealed to the connecting web adjoining adjacent walls of adjacent channel-shaped portions of the first strip element.

6. A method as claimed in claim 1, wherein the first strip element and the second strip member comprise heat-sealable material and wherein the sealing is carried out by heat and pressure at least along the lines and surfaces of contact.

7. A method as claimed in claim 1 wherein the cuts along the edges of the second strip member are not wider than the spacing between adjacent walls of adjacent channel-shaped portions of the first strip element.

8. A method as claimed in claim 5 and further comprising severing the seal between the central longitudinal portion of the second strip with the connecting web adjoining adjacent walls of adjacent channel-shaped portions of the first strip element so as to separate the containers. 

1. A method of producing containers comprising folding a first strip element of foldable packaging material transversely of its length to form a plurality of uniform, transverse, channel-shaped portions in a continuous series in the element, applying a second strip member of foldable packaging material to the upper edges of the the transverse channel-shaped portions, forming spaced, transverse cuts along the edges of the second strip member to form flaps, said cuts extending inwardly from the outer edges of the second strip member, folding the lateral longitudinal side edges of the second strip member down against the end edges of the transverse, channel-shaped portions to close the open ends thereof, portions of the inner surface of the second strip member contacting the edges of the first strip element and sealing the contacting inner surface portions to the edges, the step of forming the cuts preceeding the step of sealing the contacting inner surface portions to the edges.
 2. A method as claimed in claim 1 and further comprising forming in the second strip member two spaced, parallel, longitudinal fold lines inwardly of the edges thereof, the cuts extending from the edges of the second strip member inwardly to the adjacent fold lines.
 3. A method as claimed in claim 1 wherein each flap formed by the spaced, transverse cuts has a width and a length at least equal to the width and the length, respectively of the transverse channel-shaped portions of the first strip element.
 4. A method as claimed in claim 1 wherein the cuts are formed along the edges of the second strip member before the longitudinal side edges of the second strip member are folded down against the end edges of the transverse, channel-shaped portions of the first strip element.
 5. A method as claimed in claim 2 wherein the central longitudinal portion of the second strip member between the fold lines is sealed to the connecting web adjoining adjacent walls of adjacent channel-shaped portions of the first strip element.
 6. A method as claimed in claim 1, wherein the first strip element and the second strip member comprise heat-sealable material and wherein the sealing is carried out by heat and pressure at least along the lines and surfaces of contact.
 7. A method as claimed in claim 1 wherein the cuts along the edges of the second strip member are not wider than the spacing between adjacent walls of adjacent channel-shaped portions of the first strip element.
 8. A method as claimed in claim 5 and further comprising severing the seal between the central longitudinal portion of the second strip with the connecting web adjoining adjacent walls of adjacent channel-shaped portions of the first strip element so as to separate the containers. 